Foils are generally employed for packaging consumables and foodstuffs. In order to preserve the freshness of packaged consumables or foodstuffs, foils having a gas impermeable layer are employed (for example DE 102004062204 A1). The gas impermeable layer prevents the entry and the exit of gases. It should in particular be prevented thereby, that oxygen has access to the consumables, which would have promoted spoiling and growth of mold, and at the same time prevent loss of protective gases which are introduced into the packaging, such as nitrogen or carbon dioxide. Such gas impermeable layers are comprised for example essentially of polyamide coated cellulose film, ethylene-vinyl alcohol polymers (EVOH) or other vinyl alcohol polymers (PVOH) or are built up as multiple layers of these materials. In order to protect the consumables against drying, the packaging foils are conventionally also provided with a supplemental layer for blocking water vapor. In order to make these impermeable layer foils fusible, these are conventionally provided with a sealing layer, such as for example polyolefins and in particular polyethylene.
The impermeable foil of polyamide and/or EVOH is by itself water vapor permeable and exhibits poor sealing characteristics, that is, it is not suitable for bonding or fusing, as is necessary for packaging of consumables and food stuffs as a rule. These supplemental layers serving to block water vapor exhibit good sealing characteristics, so that as a result of this layer, on the one hand, a fusible packaging material is obtained and, on the other hand, this packaging foil exhibits in the generally desired matter the supplemental water vapor impermeability.
For certain consumables and food stuffs, in particular for example in the case of raw sausages such as Landjaeger sausages, salami and the like, and also in the case of certain sorts of hard cheeses, such an air and water impermeable packaging is however not optimal. Such a packaging prevents on the one hand the penetration of oxygen and therewith prevents growth of mold, the packaged consumables however cannot dry, so that the residual moisture present in the inside of the consumables, such as raw sausages, leads to an undesired softening of the consumables. In order to prevent this softening of the sausages, until now perforated packaging foils have been employed. These foils may allow the drying of the packaged consumables, but on the other hand, the consumables are exposed to oxygen through the perforations, which could lead to formation of mold. Further, it is known to treat the surface of consumables, such as raw sausages and hams, with substances such as the preservative agents calcium sorbate or “artificial mold”, which prevent the growth of mold. Such a surface treatment is however an additional involved process step in the production of the consumables.